1. Field of the Invention
The present invention relates generally to absorbent pads for absorbing fluid from packaged food products and, more particularly, to absorbent pads having a tubular cross section. The pads are adapted for use independently or with a tray having channels and a generally flat section disposed above the bottom of the channels. The tubular absorbent pads may be disposed in the channels of the tray.
2. Description of the Prior Art
It is common practice to store a food product such as meat, poultry and the like, in packages having a food supporting tray and an absorbent pad(s) of suitable material to absorb fluids exuded by the food product. There are presently two principal types of absorbent pads used in such packaging. In the first type, the pad is comprised of a plurality of absorbent layers or a mat of material, and an overlying plastic sheet. The plastic sheet is perforated to permit moisture to seep through to the absorbent layers. In the second type, a plurality of absorbent sheets are encapsulated between top and bottom plastic sheets, which are sealed along the edges thereof. The top plastic sheet is not perforated and therefore moisture impermeable. The bottom sheet is perforated to permit moisture to migrate through to the absorbent layers by capillary action. The configuration of the holes is arranged so as to allow moisture to flow only in a single direction. Accordingly, when water seeps into and is absorbed by the absorbent layers, the weight of the food placed on top of the pad which tends to normally squeeze the absorbent pad does not cause moisture to migrate from the absorbent material to the outside of the pad. Since the top plastic sheet is liquid impermeable, the food is prevented from making contact with the absorbent portion of the pad. To enhance moisture retention, synthetic super absorbent materials can be added between the layers of absorbent material.
Miller U.S. Pat. No. 4,410,578 discloses an absorbent pad for use in a receptacle to contain and display food products. The pad includes a mat of liquid absorbent material, an upper liquid impermeable plastic sheet overlying the absorbent mat, and a bottom plastic sheet underlying the absorbent mat. At least one of the sheets is perforated. A plurality of spacer elements are situated between the top and bottom sheets to maintain separation under a compressive load caused by the weight of the food. Any fluids exuded from the food flow around the pad and enter the mat by capillary action through the perforated openings in the bottom sheet.
Miller U.S. Pat. No. 4,321,997 discloses a receptacle for moisture exuding food products including a supporting tray and an absorbent pad disposed within the tray. The absorbent pad comprises a mat of liquid absorbent material, an upper liquid impermeable plastic sheet overlying the absorbent mat, and a bottom plastic sheet underlying the mat. At least one of the plastic sheets is perforated to permit the flow of liquid through the plastic and into the absorbent mat. A spacer structure is provided between the plastic sheets to maintain separation under the weight of the food product.
Miller U.S. Pat. Nos. 4,382,507 and 4,275,811 disclose an absorbent pad for use in a tray containing food products. The absorbent pad includes a mat of paper wadding a layer of wood fluff. A plastic liquid impermeable sheet overlies one side of the mat, and a plastic perforated sheet overlies the opposite side of the mat.
Rhodes et al. U.S. Pat. Nos. 4,940,621, 5,055,332 and 5,022,945 disclose an absorbent pad for food products including an upper and lower plastic film, at least one of which is perforated, and an intermediate absorbent layer sandwiched between the plastic layers. The intermediate absorbent layer includes a series of juxtaposed and overlapping absorbent material fibers with super-absorbent granules dispersed throughout the absorbent layer and supported by the absorbent material fibers in the spaces between the fibers. The upper and lower film layers are attached to each other along opposite marginal edges thereof to retain the absorbent layer therebetween.
Goodwin U.S. Pat. No. 4,756,939 discloses an absorbent pad including a mat of fluid absorbent material having oppositely facing flat surfaces and a cover fabricated from a liquid impermeable material enclosing the mat. The cover has two oppositely facing substantially flat imperforate surfaces corresponding to the oppositely facing surfaces of the mat, and side portions corresponding to the sides of the mat. At least two of the side portions of the cover have a plurality of perforations to permit passage of the fluid from the food through the cover and into the mat.
Kannankeril et al. U.S. Pat. No. 5,176,930 discloses a food package and absorbent pad in which the rate of absorbency is ostensibly increased by providing an intermediate layer of absorbent material which extends to the periphery of the pad to wick liquids into the pad.
Each of these absorbent pad arrangements have certain disadvantages. Specifically, they have a generally flat profile which requires a relatively large amount of polyethylene for the plastic layer(s). In addition, because the food is placed on the top of the pad, the pressure imposed on the pad by the weight of the food decreases the capability of the pad to absorb moisture, and can cause the absorbed fluids to flow back out into the package causing rapid bacterial growth, food spoilage, and discoloration.